There is an idea floating around that uBlock Origin is a lesser branch relative to uBlock[1].
The current reality is that there are two branches, not an official one and a lesser one. I keep developing my branch the same way and in the same spirit I have since the beginning of uBlock in June 23, 2014.
You are more likely than anywhere else to find a neutral explanation in this Wikipedia article for the differences in features between uBlock Origin and uBlock.
[1] An example. Another one.
pronounced you-block origin (/ˈjuːˌblɒk/) — you decide what enters your browser.
English,
Chinese (中文),
Korean (한국어)
An efficient blocker add-on for various browsers. Fast, potent, and lean.
uBlock Origin (or uBlock₀) is not an ad blocker; it's a general-purpose blocker. uBlock₀ blocks ads through its support of the Adblock Plus filter syntax. uBlock₀ extends the syntax and is designed to work with custom rules and filters.
That said, it's important to note that using a blocker is NOT theft. Don't fall for this creepy idea. The ultimate logical consequence of blocking = theft is the criminalisation of the inalienable right to privacy.
Ads, "unintrusive" or not, are just the visible portions of privacy-invading apparatus entering your browser when you visit most sites nowadays. uBlock₀'s main goal is to help users neutralize such privacy-invading apparatus — in a way that welcomes those users who don't wish to use more technical, involved means (such as µMatrix).
EasyList, Peter Lowe's Adservers, EasyPrivacy and Malware domains are enabled by default when you install uBlock₀. Many more lists are readily available to block trackers, analytics, and more. Hosts files are also supported.
Once you install uBlock₀, you may easily un-select any of the pre-selected filter lists if you think uBlock₀ blocks too much. For reference, Adblock Plus installs with only EasyList enabled by default.
Quick guide: popup user interface
For advanced usage, read about dynamic filtering and more on uBlock₀'s wiki.
Chromium [2]
Firefox
[1] Details of the benchmark available at Firefox version: benchmarking memory footprint.
[2] Important note: There is currently a bug in Chromium 39+ which causes a new memory leak each time the popup UI of an extension is opened. This affects all extensions. Keep this in mind when measuring Chromium's memory usage. In the benchmarks, I avoided opening the popups completely.
uBlock₀ is also easy on the CPU
Details of the benchmark available in this LibreOffice spreadsheet.
Being lean and efficient doesn't mean blocking less
For details of benchmark, see
uBlock₀ and others: Blocking ads, trackers, malwares.
Feel free to read about the extension's required permissions.
You can install the latest version manually, from the Chrome Store, or from the Opera store.
Alternatively, you can install chrisaljoudi/uBlock from Chrome store. Slightly different feature set, same performance.
Firefox Add-ons web site, or install manually by downloading the latest uBlock0.firefox.xpi file, and by dragging the downloaded xpi file to your add-on page.
Alternatively, you can install chrisaljoudi/uBlock from Firefox Add-ons homepage. Slightly different feature set, same performance, proper support for legacy Firefox-based browsers.
For Firefox legacy versions -- prior to Firefox 29 -- it is best to install chrisaljoudi/uBlock as it has official support for legacy Firefox versions.
There is no support for Safari for uBlock Origin.
Best is that you install chrisaljoudi/uBlock, which has official support for Safari.
To benefit from uBlock Origin's higher efficiency, it's advised that you don't use other inefficient blockers at the same time (such as AdBlock or Adblock Plus). uBlock₀ will do as well or better than most popular ad blockers.
See the releases pages for a history of releases and highlights for each release.
Free. Open source. For users by users. No donations sought.
Without the preset lists of filters, this extension is nothing. So if ever you really do want to contribute something, think about the people working hard to maintain the filter lists you are using, which were made available to use by all for free.
You can contribute by helping translate uBlock₀ on Crowdin.